This research proposal is to test the hypothesis that the aminoacid, taurine, may play a part in the central nervous system depressant properties of ethanol. Recent preliminary work in our laboratory showed that taurine (i.c.v.) increased ethanol-induced sleep time in rats. In addition TAG, a taurine antagonist (6-aminomethyl-3-methyl-4H-1,2,4-benzothiadiazine-1,1-dioxice HC1) reduced the effect of taurine in the presence of ethanol and also TAG (i.c.v.) decreased ethanol-induced sleep time when ethanol was administered alone. In order to explore the possible relationship between taurine and ethanol, mice selectively bred for differential sensitivity to ethanol are used. These selectively bred mice the so-called ethanol insensitive "Short Sleep, SS", and the ethanol sensitive "Long Sleep, LS" differ in the central nervous system sensitivity to the depressant effects of ethanol. This project is designed to assess the behavioral response (escape attempts) and the hypnotic effect (sleep time) of ethanol with taurine and TAG in LS and SS mice. The experiments will show the effects of taurine alone, ethanol alone and TAG alone. Also the interactions between taurine and ethanol as well as TAG and ethanol are examined. The various doses of drugs selected in the research proposal are used to obtain dose-response relationships in the different experiments. The analyses of the data from the dose-response curves may give an idea as to the type of interaction occurring between the drug and ethanol. The approach taken by this research project might help to indicate a possible involvement of taurine in the effect of ethanol when subhypnotic and hypnotic doses of ethanol are used.